Well it seems I'm another member of the "shuddering diff when hot" club. 09 GT with only 3k miles.

Took it to the dealer today and they tell me "can't think what it could be, fluid looks fine". Thankfully they at least witnessed the problem on a ride along and documented it.

From my searches I see the consensus seems to be to replace the Mazda fluid with Redline or Ford fluid. They wouldn't entertain that. Warranty and all that.

Has anyone had any luck with a dealer/Mazda fixing this issue or has everyone had to go the diy/external route?

Thanks,
HondaRider

PS. Posted this the other day in incorrect forum sorry. Now moved here.

 

I'm using Redline fluid and I have no problems. I used a Group 5 gear oil for a while and had no problems with that either, even though the Group 5 oil is supposed to be so slippery that it requires a friction-enhancing additive to make the limited-slip function work properly. (I did have trouble with the Group 5 oil being too slippery for the transmission synchronizers, though.)

Since shuddering is the standard misbehavior associated with gear oil that's too slippery, maybe some friction-enhancing additive will help you as well. Googling "Limited Slip Additive" came up with a bunch of options, the first being AMSOil, and I've had good experience with their products in the past. I've used their motor oil in all my cars, including my RX-8.

To hell with the Mazda dealer. Get it done at an indy shop. Mazda can't void your warranty if you use oil that meets or exceeds their minimum spec.

 

The dealer here retorqued the axle nuts and added friction modifier to mine per Mazda tech line (as written in the service wirte-up). Seems to be gone, but it's getting swapped to synthetic before it hits the track.

 

Thats what they did for me.

 

Thanks for the guidance. Took a couple visits and getting a good service tech but they replaced the fluid and added Mazda friction modifier. So far so good.

 

I sarted to feel the shutter at about 45-50k km, I changed the fluid in the tranny and diff for syntectic lucas gear oil and its been fine since then, diff seems smoother as well in tight corners and transmission feels less notchy, for me Its a 50k maintenance to replace those fluids, doing the spark plugs at the same time usualy

 

When I changed my differential gear oil with Mobil 75w90 at 3500 miles there was a handful of "metal mud" on the bottom plug magnet, so I think you needed that flush anyway even though the manual doesn't require it. I changed it again at 27k miles, and just a small amount of metal.

The first flush is important just like an engine and the differential can't filter it out.

 

You got most all of that backwards. The shuddering is the limited slip grabbing and releasing. The modifier makes the oil have more slip, which reduces the grabbing and releasing effect.


.

 

i never had any problems with mine ... yea im s1 but its the same ...

and i change my fluid every 10-15 k miles. **** i mean its just like20 bux and 1 hr of my sweet time, i dont see why not.